1. Field of the Invention
This invention relates to diecast coupling members such as pocket plates, methods for making such coupling members and clutch assemblies including such coupling members.
2. Background Art
Pocket plates or members for use in one-way ratcheting type coupling or clutch assemblies are typically formed using powdered ferrous metals. In contrast to other metal-forming techniques, powdered metal parts are shaped directly from powder, whereas castings originate from molten metal.
Other methods of forming pocket plates have been tried in an attempt to reduce cost. For example, U.S. Pat. No. 6,333,112 discloses a laminated pocket plate. U.S. Patent Publication No. 2008/0135369 discloses a stamped clutch pocket plate. U.S. Pat. No. 6,125,980 discloses a pocket plate integrated within a hub such as by casting or molding to form an integral assembly. The hub comprises an aluminum alloy casting or a phenolic molding. The pocket plate itself is preferably a powdered metal part.
For purposes of this application, the term “coupling” should be interpreted to include clutches or brakes wherein one of the plates is drivably connected to a torque delivery element of a transmission and the other plate is drivably connected to another torque delivery element or is anchored and held stationary with respect to a transmission housing. The terms “coupling,” “clutch” and “brake” may be used interchangeably.